Method of working metals, ores, and the like.



Patented Nov. 2, 1909.

0. FR METHOD 0? WORKING METALS, 0113s, AND THE LIKE.

APPLIOATIOH FILED AUG. 31, 1905.

To all whom it may concern:

Be it known that I, Or'ro FRICK, a subject of the King of Sweden, and aresident of Saltsjiibaden, in the Kingdom of Sweden,

have invented new and useful Improvements in Methods of WVorking Metals,Ores, and the Like, of which the following is a specification, referencebeing had to the drawing accompanying and forming a part hereof.

This invention relates to an improved method of working, whereby thepower factor may be increased in the melting of metals, ores, and thelike, and in reducing ores by means of electric transformer furnaces.

In melting metals and the like the melting of the principal parts of thecharge as well as the following treatment, 2. 6., the refining and theaddition of special materials or chemical combinations for impartingspecial qualities to the product, and so forth, were hitherto usuallyaccomplished in one and the same'furnace, the material to be melted andI the melted mass forming a single conductor of approximately constantcross-section.

'The said method has, however, a great disadvantage, inasmuch as it isdifficult to treat large charges by it, the self-induction being veryconsiderable and, consequently, the power factor becoming very small.The power factor decreases nearly in proportion to the increase in thecross-section and in the weight of the charge.

, 'The British patent No. 28,805 of Charles .Prosper Eugene Schneider,dated December 31st, 1903, discloses an electric transformering toolarge lag, a furnace being used wherein the larger part of themelting-room has a considerably reduced cross-section.

The object of the present invention islto make it-possible to treatcharges of any size by means of transformer-furnaces.

The invention consists in carrying out the treatment in two separatetransformer-furnaces the first of whichis constructed for acomparatively small charge and. great consumption of energy, essentiallyfor melting the principal parts of the material to be produced, whilethe second-furnace, whichis constructed for a large. charge and iscapable of storing the melted materials as they are continuously orintermittently poured into it from the first. furnace, is adapted for acomparatively small consumption of energy andis mainly used to-keep themelted ma- Specification of Letters Patent.

furnace, the object of which is to render it u, possible to treat largecharges, while obviat- Unirn' earns PATENT orrron.

OTTO ERICK, OF SALTSJ6BADEN, SWEDEN.

METI-IGID OF WORKING METALS, ORES, AND THE LIKE.

terials at constant heat until the whole charge is ready. The favorableinfluence of this method on the power-factor in the pnmary circuit willbe easily understood by an example. Supposing the angle of lag to be ythe same can be estimated by the following equation:

an.q)-c. WP+Ws if the current necessary for the magnetization. of thetransformer core is small, so that the ampere-turns of the primarywinding may be supposed to be equal tot/hose of the bath, which ispractically tllx, case inevery well-designed transformer.

In the above equation a constant,- frequency per second, r resistance ofthe melting-bath in ohms, magnetic resist ance of the primary flux ofleakage. W magnetic resistance of the secondary flux of leakage. Fromthis formula it is seen that tan. go is universally proportional to theresistance of the melting bath. The resistance of the bath evidentlydecreases with increasing crosssection and weight of charge. Thepower-factor, or cosine mp deincreases as tan. p increases.Consequently, the power-factor decreases with increasing cross-sectionand weight .of bath. If, for instance, one transformer-furnace were tobe used for melting a charge of tons of steel,

the cross-section of the melting-bath being constant, the lag betweencurrent and voltage, for instance at periods a second, would correspondto a power factor cos. =0.20,

that is to say the'current would be ='5 times larger than if.the powerfactor, or the real power apparent power the copper windings of thedynamo arelto be dimensioned to suit the current, it is evident thatthey must be calculated for 5 times the real power. I

If the furnace-plant be constructed acwere= 1. As the leads and PatentedNov. 2, 1am. Application filed August 31, 1905. Serial No. 276,519. i

cording to my present invention, and the larger furnace be adapted for acharge of 15 tons, then, under the same conditions, the power factor ofthis furnace is also 'cos. 91:020. As, however, the principal functionof this furnace is to maintain the molten steel at a constanttemperature, the energy consumed has, practically, only to cover lossesdue to heat radiation, and may for instance amount to only 10 per cent."of the total energy'required for the whole melting effected in thelarge furna The other 90 per cent. of the total process.

is consui'ned in the smaller energy furnace g in which the materials aremelted and which, 1

the same can be increased without difiiculty to cos. 9 0.6.. The leadsand the generator factor of thus in this case need only be calculatedfor 1 an apparent power of twice the real power,

This useful result 1S losing any advantage of r usualtransformer-furnace. Gn the coronary, further advantages are gained overthe welllsnown single transforiner-furnaces, which are not suited forcontinuous working if different products, such as alloys of steel andchro mium, tungsten, nickel, and so forth, are to produced, one afteranother It is a wellknown fact that a tronsformer-furnace must alwayshave a molten continuous bath, for which reason it is necessary to leavepart of the bath in the furnace from one charge to the next. In makingordinary carbon steels this is not very inconvenient, but in makingsteel-alloys it may not be desirable to leave a part of a charge ofniche -steel to a followin charge of chrome-steel.

hen using two furnaces, according to this invention, this inconveniencedoes not occur as the addition ofspecial materials, such as nickel,chromium, and so forth, is e which may be totally emptied after eachcharge, it being refilled from the smaller furnace.

By using two furnaces continuous working and the full continuousutilization of the available machinery "will also be improved in caseswhere the melted material requires certain time for refining, as a newcharge may be started in the small furnace during; the time thepreceding charge is being re need in the larger one.

The two furnaces may be supplied with current by means of a eaunmon,generator or by separate generators.

lin order to gain the above mentioned result it is necessary todimension the core and the primary winding of the smaller furnace insuch a manner that a higher effective voltage will beugenerated initsbath and that the greatercpart of the power will he consumed by thesaid furnace in spite of the higher resistance of the bath, The ironcore and the primary winding of the larger furnace must,'on the otherhand, he so diiued without meusioned that the bath. of the same consumesa coi'nparatively uuull amount of energy. T his is carried out in such amanner that the smaller furnace has a? magnet-core of a larg rcross-section an l is generally worked h a smaller number of turns inthe primary coil than the larger furnace.

in the drawing, Figures 1 and 2 show, in vi tical section and plan-view,respectively,

.urnace-plaut adapted to be used in carrying out the process abovedescribed.

Referring to the drawing, 1 is the smaller furnace in which the mainmelting-process is accomplished and from which the melted material isconveyed, either continuously or intermittently into the larger furnace2, which serves as a refining furnace and as a storage receptacle, untilthe whole charge is ready. and i are masonry of lire-proof or othersuitable material. and 6 are the ring-shaped crucibles inclosed in themasonry. 7 and 8 are the primary windings supplied with alternatingelectric current from the same source of current, or from two separatesources of current 9 and 10 are the magnet cores.

Having now described my invention, what I claim as new and desire tosecure. by Letters Patent is:

1. The method of increasing the power factor in treating ores and metalsby means of electric transformer furnaces, which conin melting theprincipal part of the charge in one transformer furnace, c0nvey--' ingthe melted material from the said furnace into another transformerfurnace adapted to hold an essentially larger charge than the formerone, and refining and storing the said material in the said largertransformer furnace, substantially as and for the purpose set forth.

2. The method of increasing the power factor in treating ores and metalsby means of electric transformer furnaces, which conin melting theprincipal part ofthe charge in one transformer furnace, conveying themelted material from the said furinto another transformer furnaceadapted to hold an essentially larger charge than the former one, andstoring the said material in the said larger transformer fornace,substantially as and for the purpose set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

J OTTO ERICK.

Enwnno L. ADAMs,

lam. Frances.

